This invention relates to an arrangement of stringing holes in the yoke of a racket.
Conventionally, the strike surface defined by the frame and the yoke of a racket is constituted by interweaving the strings in both longitudinal and horizontal directions. The horizontal strings are at both ends passed through opposite sides of the racket, while the longitudinal strings are at upper end, on the one hand, passed through the top of the racket and at lower end, on the other hand, a portion passed through the shoulder and remaining portion through the yoke. As shown in FIG. 5, the longitudinal strings are extended in parallel to each other. Among sixteen longitudinal strings only about six central strings are passed through the yoke while other ten strings are passed through the shoulder portion of the racket. Hence, in the yoke there are only six string holes arranged in a linear row for the strings passing thereover in sequence, as best shown in FIG. 6.
In this kind of conventional racket, the longitudinal strings at both lateral sides that are not passed through the yoke have shorter length and thus cause inferior rebound. In order to provide all longitudinal strings having more uniform lengths, a new kind of racket as referred to FIG. 1 has been recently developed, in which besides the central longitudinal strings, the lateral strings are convergently inclined with respect to the central axis, so that there are fourteen longitudinal strings in total passing through the yoke. But with the normal linear arrangement of string holes as in the yoke of a conventional racket, as shown in FIG. 7, even ten holes impairs the strength of the yoke to the point that the racket may be easily broken, and of course, the yoke cannot accommodate fourteen strings.
A modification as shown in FIG. 8 is suggested, in which the stringing holes are arranged in two rows at opposite surfaces in a form of grooves. Although this arrangement does accommodate fourteen strings, it still weakens the yoke too much to be an effective method of stringing.